Unless this goes into extreme depth about what each class should be doing then I don't think it will do a thing. The game does a horrible job as it is explaining a lot of things (I still see people going around as classes rather than jobs in high level content). Even if we got another page or tab saying 'Core Spells' where it then lists a recommended usage of said spell seeing as people don't read tooltips either. For Example,

Cure 2 - Use when a player has taken heavy damage. Use Cure in other cases.
Regen - Keep applied to the tank and use on others when there is little chance of big damage. Do not use inbetween trash pulls.

Just something to give out more information.